1. FIELD OF THE INVENTION
This invention relates to compositions of a polyphenylene ether resin, high impact polystyrene, poly (ethylene-co-methacrylic acid), poly(styrene-co-glycidyl methacrylate), and optionally a styrene-ethylene/butylene-styrene block copolymer and polyethylene, which have improved properties.
2. DESCRIPTION OF THE PRIOR ART
The polyphenylene ethers are a family of thermoplastic engineering resins known to be useful with polystyrene resins to form compositions that can be extruded and molded into articles of various shapes and sizes. The resulting products range from parts and housings for household appliances to components for automobiles.
Efforts have been made to combine the polyphenylene ether resin with still other polymers, such as polyethylene, to achieve compositions having property profiles useful for certain specialty applications. Compositions of this type have been described in the patent literature, for example, in U.S. Pat. Nos. 4,166,055 and 4,239,673 (both to Gim F. Lee, Jr.). In general, such compositions are blends of a polyphenylene ether resin, a high impact polystyrene, an elastomeric block copolymer of, e.g., styrene and butadiene, and a polyolefin such as polyethylene. Articles molded from them exhibit better resistance to chemical solvents than conventional blends of polyphenylene ether and high impact polystyrene, which is important for many commercial applications. However, shortcomings include low tensile strengths and a tendency to undergo delamination in the molded part near the gate.